Tube bending tool



July 2, 1946. c. E. ADREON TUBE BENDNG TOOL v Filed Nov. 3, 1943 2 Sheets-Sheet 1 FIGURE l. FIGURE. 2;.

FIGURE 5. 7 FIGURE 6.

. INVENTOR.

ATTORNEY FIGURE 4 Io FIGURE 3.

FIGURE: {9,

Fil ed Nov. 3; 1943 c. E. 'ADREON TUBE BENDNG moi.

2 sham-shut z AT'TO EY I Patented July 2, 1946 Carroll Adreon, Baltimore assignor'toThe Glenn L. Mar-tin Company, Middle River,'Md.,

a corporationofMaryland H Application November a, 1942, Serial Np. 508,780

This invention relate to a device for bending tubes about a predetermined radius of curvature for aselected number of degrees bend.

The difiiculties encountered in "bending small tubes accurately to a predetermined radius and for a definite angle between the ends of the tube, is well known. The problem is further involved when metals, such as the aluminum alloys; are employed. With ordinary bending, such tubes collapse, thus'altering their cross-sectional area and causing a restriction to theflow of fluid therein and very often the tubes crack along the edges of the collapsed portionif any attempt is made to straighten them.

3 Claims o1. rte-40aa manner that the 'handle, when free, will be moved. by the spring in a counter-clockwise direction in Figures 11 to 4. Forming block I4 has a portion I5 which extends under bracket 5land By this invention, a means is provided for bending tubes and accurately forming the radius curvature of the bend.

Another object of this invention is to afiord a means for maintaining a definite angleof bend inthetube. A further object of this invention is the prevention of the collapse or the alteration of the cross-sectional area of the opening in the tube while being bent.

Further and other objects will become apparent from the description of the accompanying drawings which form a part of this disclosure and in which like numerals refer to like parts.

In the drawings:

Figures 1 to 4 show the relationship of the parts of the tube bending tool during-the bending operation.

Figures 5 to 8 show the operation of the cam mechanism and the relative position of the parts during the bending operation shown in Figures 1 to 4.

Figure 9 is a sectional view through th tube bending tool device.

The tube bending tool illustrated in the drawings comprises a base member I having a cavity 2 formed in the underside thereof. The base is formed with lugs 3, each having a hole 4 for mounting the tool on a bench. On top of block I are assembled the parts for holding and bending a tube. Rigidly secured to block I is bracket 5' to which forming die 6 is securely fastened.

J Retaining member I is also secured to bracket 5. Groove 8 in member I and groove 9 in die 6 are formed with a radius equal to the outside radius of the tube to be bent. Handle I0 passes through die 6 and bracket 5 and turns freely in each member. Portion I I of handle I0 is square, while the remaining portion I 2 is round and fre to turn in block I. spring I3 is secured to the end of the handle within cavity 2 and to the block in such is retainedrthereby between portion I6 ofibracket 5.and thebase I. The configuration of cam member I8 is shown in Figures 5 to '8. This cam has a square .hole form edtherein, and fits over square portion IIof handle I0, shown in Figure-'9. .Portion I5 forms affol-lower for bam- I8 to move the formiri'gdie It. Thehol-e I1 f ormed in member I5 is-sh aped to cause forming die I4 tomove radially inwardly, shown in Figure 6, when handle I9 is moved from the position shown in Figure 5 to that of Figure 6; A more detailed description of this action will be given subsequently,

An inspection of Figures 1' to 4 and!) will show the relationship of th parts and their assembly. Member 6 is secured to portion I 6 of bracket 5. This sub-assembly and block I. are rigidly'se curedto the base. 0am 'I8-is placed in hole; I1 of the follower I5,-a-nd-the square hole I 9,, "of the eam is aligned with the holes in 'die block 6 and member I6. Handle I B is then placed in the aligned holes until the square portion II' engages the square hole I9. -Washer 20 and spring I3 are then assembled on the portion of the handle'extending within the cavity 2. Washer 20 is secured to portion I 2.

As shown in Figures 1 to 4, a tube 2| is placed in groove 8 in retainer block 1. Since forming block I4 is spaced from the die blockt, the tube extends through this space and when held against block 1, lies substantially tangent to die 6. From an inspection of Figures 1 and 5, it will be apparent that as handle I0 moves in a clockwise direction to the position shown in Figures 2 and 6, cam I8 will move follower I5 so that forming block I4 moves radially inwardly, with index 22 aligned with the zero on die 6. The groove in the die and the groove in forming block I4 are such that they engage tube 2| with a sliding fit. Further clockwise motion of handle I0 as shown. in Figures 3 and 7, will cause forming block I4 to move around die 6, and form the tube to the radius of curvature of the die. The angularity of the bend may be read in degrees. Counterclockwise motion of handle II), as shown in Figures 4 and 8, will release the forming block from engagement with the tube and die before returning the forming block to its initial position. Since the spring is so arranged that it urges the handle in a counterclockwise direction, when the desired degree of bend has been reached, the handle may be released by the operator and the tool will be mounted, for the atorv in manipulating the tubing in the tool. 3

spring will first move block [4 radially outwardly j to disengage the tube, and then return it to its initial position.

In the softer metal alloy tubes,'the bend can be j quickly and accurately effected as there is no spring-back in the metal and due to the fact that j the circumference of times during the "eration in the die and the forming block, the tube 1, will not collapse and thercross-sectionaliarea of 1 the hole in the tube will not be altered. 7 If the tube is of a material, such as brass'or 1 steel, wherein there may be a slight spring-back,

l to form n 1 merely necessary to release the forming block,

slightly when the index 22 is desired number of degrees and see if'it springs at that point. If it does, a few 3 more degrees of bending thetube will spring back 1 position. The bend of the' tubefm'ay-be checked after the bending operation as'described above.

the tube is limited at all bending operation by the, coop- ,such a tube to an, accurate bend, it is may be necessary so that to the proper angular aligned with the. check the tube to f said cam, a curved die block concentric with the pivot of said handle having a groove around the periphery thereof, a retaining means to hold said tube in the initial position tangentto said die block, a forming block having a groovetherein thereafter moves said die block bodily therewith to effect tube bending about the axis of said handle. 1 r

2. A tube bending tool comprising a base, a

handle pivoted on the base, a curved die block fixed to said base, atube restraining member fixed tothe base in spaced relation to said die block,

a cam fixed to said handle, a cam follower having an opening surrounding said cam, said opening being elongated radially ofthe handle axis wherebyih'andlepivoting movement sequentially Several types of cam action'togive asimilar motion of "the die block maybe employed but the 1 preferred 'form herein described has been found Q to be simple in construction and sufiiciently 1 1 rugged to withstand continuous usage.

It will be noted that the base member is of such between thebench top on whichthe tube bending It is to be understood thatv certain, changes, alterations, modifications and substitutions can be made without departing from the spirit and scope of theappended claims. 7, Y

I claim asmy invention:

ing anopening formed therein surrounding said cam, said opening formed to provide a follower for,

l a height that there will be sufiicient clearance,

hands of the oper and thereafterbodily therewith about the axis or said handle and a tube engaging orming. block moves the cam follower radial of thehan'dle and thereafterbodily'therewith about the axis of said handle and a tube engaging-forming block fixed to said cam follower, the movement of which eifects the bending of a tube about said die block.

3. A tube bending tool' comprising a lbas'e, a handle pivotedon the'base, a curved dieblock fixed to said base, a tube restraining member fixed to the base in spaced relationto said die block, a cam fixed to said handle, a 'camfollower having an opening surrounding said .cam, said opening being elongated radially of the handle axis whereby handle-pivoting movement sequentially moves the cam follower radial of the handle secured on one side only to said cam followeri'the movement of which efiects the bending of a tube about said die block.

' .cARRoLL E. 'ADn o'Nfl 

